package com.cenxi.utils;

import com.alibaba.excel.enums.CellDataTypeEnum;
import com.alibaba.excel.metadata.Head;
import com.alibaba.excel.metadata.data.WriteCellData;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.style.column.AbstractColumnWidthStyleStrategy;
import org.apache.poi.ss.usermodel.Cell;

import java.util.HashMap;
import java.util.List;
import java.util.Map;


/**
 * excel宽度风格策略
 *
 * @author admin
 * @date 2023/01/31
 */
public class ExcelWidthStyleStrategy extends AbstractColumnWidthStyleStrategy {
    /** 最大列宽 */
    private static final int MAX_COLUMN_WIDTH = 255;
    /** 最小列宽 */
    private static final int MIN_COLUMN_WIDTH = 25;

    private  final Map<Integer, Map<Integer, Integer>> CACHE = new HashMap<>(8);

    @Override
    protected void setColumnWidth(WriteSheetHolder writeSheetHolder, List<WriteCellData<?>> cellDataList, Cell cell, Head head,
                                  Integer relativeRowIndex, Boolean isHead) {
        boolean needSetWidth = isHead || !cellDataList.isEmpty();
        if (!needSetWidth) {
            return;
        }
        Map<Integer, Integer> maxColumnWidthMap = CACHE.computeIfAbsent(writeSheetHolder.getSheetNo(), k -> new HashMap<>(16));
        Integer columnWidth = dataLength(cellDataList, cell, isHead);
        if (columnWidth < 0) {
            return;
        }
        if (columnWidth > MAX_COLUMN_WIDTH) {
            columnWidth = MAX_COLUMN_WIDTH;
        }
        if (columnWidth < MIN_COLUMN_WIDTH) {
            columnWidth = MIN_COLUMN_WIDTH;
        }
        Integer maxColumnWidth = maxColumnWidthMap.get(cell.getColumnIndex());
        if (maxColumnWidth == null || columnWidth > maxColumnWidth) {
            maxColumnWidthMap.put(cell.getColumnIndex(), columnWidth);
            writeSheetHolder.getSheet().setColumnWidth(cell.getColumnIndex(), columnWidth * 256);
        }
    }

    private Integer dataLength(List<WriteCellData<?>> cellDataList, Cell cell, Boolean isHead) {
        if (isHead) {
            return cell.getStringCellValue().getBytes().length;
        }
        WriteCellData<?> cellData = cellDataList.get(0);
        CellDataTypeEnum type = cellData.getType();
        if (type == null) {
            return -1;
        }
        switch (type) {
            case STRING:
                return cellData.getStringValue().getBytes().length;
            case BOOLEAN:
                return cellData.getBooleanValue().toString().getBytes().length;
            case NUMBER:
                return cellData.getNumberValue().toString().getBytes().length;
            default:
                return -1;
        }
    }
}
